A biophobic interface modifier, its preparation method and application

Abstract

The application discloses a kind of amphiphobic interface modifiers and its preparation method and application, belong to the technical field of oil exploitation.The molecular formula of amphiphobic interface modifier is C 13 H 22 F7NO4Si, with structure as shown in formula I.The application further provides a preparation method of the amphiphobic interface modifier and its application and amphiphobic oil displacement agent.After the rock surface is modified by the amphiphobic interface modifier of the application, the adhesion of the rock to oil and water becomes extremely low, which can greatly reduce the boundary slip resistance of oil and water in micro-pore channels;Under the same pressure, the effective percolation capacity of the fluid is enhanced, and the residual oil in the micro-pore channels that cannot be driven by traditional water flooding can be started.

Description

Technical Field

[0001] This invention belongs to the field of petroleum extraction technology, specifically relating to a dual-hydrophobic interface modifier, its preparation method, and its application. Background Technology

[0002] As a strategic energy resource, the efficient extraction and utilization of petroleum directly impacts energy security and economic development. With most oilfields entering the high water-cut development stage, traditional primary and secondary oil recovery methods are insufficient to meet the ever-increasing demand for crude oil, making tertiary oil recovery (EOR) technology an inevitable choice. Chemical flooding, as one of the core technologies of tertiary oil recovery, improves the interfacial properties between oil, water, and rock by injecting chemical agents, thereby driving the flow of residual oil. Traditional chemical flooding agents mainly include surfactants and polymers: surfactants, with their amphiphilic structure, can significantly reduce the interfacial tension between oil and water, promoting crude oil emulsification and stripping of the oil film; polymers expand the swept volume by thickening the aqueous phase and improving the mobility ratio. However, these methods are often limited in effectiveness under harsh reservoir conditions; surfactants are easily adsorbed and lost by the rock, while polymers are prone to shear degradation.

[0003] In recent years, a dual-hydrophobic interface modifier possessing both hydrophobic and oleophobic properties has attracted attention as an emerging direction for chemical flooding. Its working principle lies in the fact that the dual-hydrophobic interface modifier forms a stable, ultrathin nanoscale film on the rock surface through chemical adsorption, giving the rock surface both hydrophobic and oleophobic properties. This modification can significantly reduce the capillary resistance of the aqueous and oil phases at the pore throat, while suppressing the water-locking and Jamin effects, making it easier for both oil and water phases to peel off from the rock surface, thus exhibiting unique oil displacement potential in low-to-medium permeability reservoirs.

[0004] Developing a dual-hydrophobic interface modifier that possesses strong anchoring capabilities, is economical and environmentally friendly, and can effectively improve crude oil recovery has become a critical technical bottleneck that urgently needs to be overcome in the field of chemical flooding. Summary of the Invention

[0005] This invention provides a dual-hydrophobic interface modifier, its preparation method, and its application to solve the problems of easy adsorption loss, weak anchoring ability, and poor crude oil recovery effect of existing chemical oil displacement agents.

[0006] The technical solution adopted to achieve the above objectives is to provide a bihydrophobic interface modifier, the molecular formula of which is C0. 13 H 22 F7NO4Si has the structure shown in Formula I: .

[0007] This invention also provides a method for preparing the above-mentioned bihydrophobic interface modifier, comprising the following steps: (1) Under an inert atmosphere, perfluorobutyric acid was dissolved in a solvent, thionyl chloride was added to carry out an acyl chloride reaction, and the intermediate product was obtained after removing the solvent. (2) Dissolve the intermediate product and the acid-binding agent in a solvent, and then add (3-aminopropyl)triethoxysilane to carry out a substitution reaction to obtain the product.

[0008] Preferably, the solvent in step (1) is dichloromethane; the molar ratio of perfluorobutyric acid and thionyl chloride is 1:(1~1.4).

[0009] More preferably, the molar ratio of perfluorobutyric acid to thionyl chloride is 1:1.2.

[0010] Preferably, the acyl chloride reaction includes the following steps: first reacting under ice bath conditions for 20-30 minutes, then heating to 45-55°C and reacting for 3-4 hours.

[0011] More preferably, the acyl chloride reaction includes the following steps: reacting for 25 minutes under ice bath conditions, followed by heating to 50°C and reacting for 3.5 hours.

[0012] Preferably, after the acyl chlorination reaction is completed, the temperature is raised to 70°C to evaporate the solvent in step (1) to obtain the intermediate product.

[0013] Preferably, in step (2), the solvent is tetrahydrofuran; the acid-binding agent is triethylamine; and the molar ratio of the intermediate product, the acid-binding agent and (3-aminopropyl)triethoxysilane is 1:(1.2~1.4):(1.1~1.3).

[0014] More preferably, the molar ratio of the intermediate product, the acid-binding agent, and (3-aminopropyl)triethoxysilane is 1:1.3:1.2.

[0015] More preferably, the substitution reaction is carried out at a temperature of 45-55°C for 8-10 hours.

[0016] More preferably, the substitution reaction is carried out at a temperature of 50°C for 9 hours.

[0017] This invention also provides the application of the above-mentioned dual-hydrophobic interface modifier in the preparation of dual-hydrophobic oil displacement agents.

[0018] The present invention also provides a dual-hydrophobic oil displacement agent, comprising the above-mentioned dual-hydrophobic interface modifier, anionic surfactant and organic solvent.

[0019] Preferably, the anionic surfactant is sodium dodecylbenzenesulfonate and the organic solvent is anhydrous ethanol.

[0020] Preferably, the dual-hydrophobic oil displacement agent comprises 0.5 wt% of the above-mentioned dual-hydrophobic interface modifier, 1 wt% sodium dodecylbenzenesulfonate, 5 wt% anhydrous ethanol and 93.5 wt% water.

[0021] This invention also provides the application of dual-hydrophobic interface modifiers in crude oil recovery.

[0022] This invention also provides the application of dual-hydrophobic interface modifiers in drag reduction of oilfield oil and gas gathering and transportation pipelines.

[0023] The present invention has the following beneficial effects: The preparation method of the dual-hydrophobic interface modifier of the present invention is simple and has a stable chemical structure. When applied to rock treatment, it can make the rock surface exhibit dual-hydrophobic and oleophobic characteristics, significantly reducing surface energy and achieving an effective transformation of wettability. With its strong hydrophobic ability, the modifier is conducive to the backflow of aqueous phase, reducing the risk of water lock and thus clearing oil and gas channels. At the same time, by balancing hydrophobic and oleophobic abilities, it can ensure good fluid mobility in pores, on the one hand avoiding water phase retention, and on the other hand promoting the effective stripping of oil film during water drive. It can further liberate oil and gas channels and ultimately help improve crude oil recovery. Attached Figure Description

[0024] Figure 1 The image shows the FTIR characterization results of the dual-hydrophobic interface modifier. Figure 2 As a bihydrophobic interface modifier 1 Figure of H NMR characterization results; Figure 3 The images show the appearance of core sections after adding formation water and simulated oil, respectively; (a) shows the appearance of formation water droplets spreading on the core section; (b) shows the appearance of simulated oil droplets spreading on the core section. Figure 4 Static contact angle diagrams of core sections treated with a dual-hydrophobic interface modifier after adding formation water and simulated oil respectively; where (a) is the static contact angle diagram of the core section treated with the dual-hydrophobic interface modifier after adding formation water; (b) is the static contact angle diagram of the core section treated with the dual-hydrophobic interface modifier after adding simulated oil. Figure 5 The advance and retreat angles of core sections treated with a dual-hydrophobic interface modifier after dripping formation water and simulated oil are shown in the figures; (a) shows the advance and retreat angles of core sections treated with a dual-hydrophobic interface modifier after dripping formation water; (b) shows the advance and retreat angles of core sections treated with a dual-hydrophobic interface modifier after dripping simulated oil. Figure 6 The pressure gradient variation curve of the 0.4PV modified system is shown in the figure. Figure 7 The pressure gradient variation curve of the 0.8PV modified system is shown in the figure. Figure 8 The pressure gradient variation curve of the gas-driven system with 0.2PV modification is shown in the figure. Figure 9 The pressure gradient variation curve of the gas-driven system with 0.4PV modification is shown in the figure. Figure 10 The pressure gradient variation curve of the gas-driven system with 0.6PV modification is shown in the figure. Figure 11 The pressure gradient variation curve of the gas-driven system with 0.8PV modification is shown in the figure. Figure 12 This is a graph showing the efficiency of oil washing. Detailed Implementation

[0025] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0026] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0027] Example 1 A bihydrophobic interface modifier with the molecular formula C 13 H 22 F7NO4Si has the structure shown in Formula I: .

[0028] This embodiment also provides a method for preparing the above-mentioned bihydrophobic interface modifier, including the following steps: (1) Under a nitrogen atmosphere, 1 mol of perfluorobutyric acid and 20 mL of dichloromethane were added to a dry reaction flask and mixed. 1.2 mol of thionyl chloride was added dropwise through a constant pressure separatory funnel. The reaction was first carried out under ice bath conditions for 25 min, and then heated to 50 °C and reacted for 3.5 h. After the reaction was completed, the temperature was raised to 70 °C and the stopcock of the constant pressure separatory funnel was closed. Dichloromethane was distilled off to obtain the intermediate product. (2) Add 1 mol of intermediate product, 1.3 mol of triethylamine and 20 mL of tetrahydrofuran to a dry reaction flask and mix well. Then add 1.2 mol of (3-aminopropyl)triethoxysilane dropwise through a constant pressure separatory funnel and carry out the substitution reaction at 50 °C for 9 h to obtain the product.

[0029] The dual-hydrophobic interface modifier prepared in this embodiment was characterized by FTIR using a SHIIMADZU-IRTracer-100 Fourier Transform Infrared Spectrometer (Shanghai Haoliang Optoelectronic Equipment Co., Ltd.); and the sample was characterized by nuclear magnetic resonance spectroscopy using a Bruker DRX-600 NMR spectrometer (Beijing Jielu Science and Trade Co., Ltd.). 1 H NMR characterization, the results are as follows: Figure 1 and Figure 2 As shown.

[0030] from Figure 1The infrared detection results show that at a wavenumber of 3220 cm⁻¹ -1 A peak of NH bond stretching vibration appeared at a wavenumber of 1704 cm⁻¹. -1 The appearance of a C=O bond stretching vibration peak indicates the successful synthesis of the target product. From... Figure 2 of 1 HNMR characterization revealed that the proton peak at chemical shift δ = 0.65 (t, 2H) belonged to the methylene group; the proton peak at δ = 1.22 (t, 9H) belonged to the methyl group; the proton peaks at δ = 1.69–1.74 (m, 2H) belonged to the methylene group; the proton peaks at δ = 3.37–3.45 (m, 2H) belonged to the methylene group; the proton peak at δ = 3.82 (q, 6H) belonged to the methylene group; and the proton peak at δ = 7.15 (s, 1H) belonged to the amide group. Figures 1-2 The results show that the bihydrophobic interface modifier of the present invention has been successfully synthesized with high purity.

[0031] Example 2 A bihydrophobic interface modifier having the molecular formula and structure shown in Example 1.

[0032] This embodiment also provides a method for preparing a bihydrophobic interface modifier, including the following steps: (1) Under a nitrogen atmosphere, 1 mol of perfluorobutyric acid and 20 mL of dichloromethane were added to a dry reaction flask and mixed. 1 mol of thionyl chloride was added dropwise through a constant pressure separatory funnel. The reaction was first carried out under ice bath conditions for 20 min, and then heated to 45 °C and reacted for 4 h. After the reaction was completed, the temperature was raised to 70 °C and the stopcock of the constant pressure separatory funnel was closed. Dichloromethane was distilled off to obtain the intermediate product. (2) Add 1 mol of intermediate product, 1.2 mol of triethylamine and 20 mL of tetrahydrofuran to a dry reaction flask and mix well. Then add 1.1 mol of (3-aminopropyl)triethoxysilane dropwise through a constant pressure separatory funnel and carry out the substitution reaction at 45 °C for 10 h to obtain the product.

[0033] Example 3 A bihydrophobic interface modifier having the molecular formula and structure shown in Example 1.

[0034] This embodiment also provides a method for preparing the above-mentioned bihydrophobic interface modifier, including the following steps: (1) Under a nitrogen atmosphere, 1 mol of perfluorobutyric acid and 20 mL of dichloromethane were added to a dry reaction flask and mixed. 1.4 mol of thionyl chloride was added dropwise through a constant pressure separatory funnel. The reaction was first carried out under ice bath conditions for 30 min, and then heated to 55 °C and reacted for 3 h. After the reaction was completed, the temperature was raised to 70 °C and the stopcock of the constant pressure separatory funnel was closed. Dichloromethane was distilled off to obtain the intermediate product. (2) Add 1 mol of intermediate product, 1.4 mol of triethylamine and 20 mL of tetrahydrofuran to a dry reaction flask and mix well. Then add 1.3 mol of (3-aminopropyl)triethoxysilane dropwise through a constant pressure separatory funnel and carry out the substitution reaction at 55 °C for 8 h to obtain the product.

[0035] Experiment Example 1: Static Contact Angle, Advance Angle, and Retreat Angle Test After cleaning and drying natural core slices, formation water and simulated oil were dripped onto them, and the initial contact angle state of the core slices before treatment was recorded. The dual-hydrophobic interface modifier prepared in Example 1 of this invention was formulated as a dual-hydrophobic oil displacement agent. The formulation of the dual-hydrophobic oil displacement agent was: 0.5 wt% of the dual-hydrophobic interface modifier prepared in Example 1, 1 wt% sodium dodecylbenzenesulfonate (SDBS), 5 wt% anhydrous ethanol, and 93.5 wt% water. Another set of identical core slices was immersed in the dual-hydrophobic oil displacement agent for 20 min. After the reaction, the slices were cleaned and dried in a 60℃ oven for 2 h to remove surface moisture. Formation water and simulated oil were dripped onto the surface of the core slices respectively, and their surface characteristics were recorded. The results are as follows: Figures 3-5 As shown.

[0036] from Figure 3 As can be seen, when formation water and simulated oil are added to an untreated core slice, the resulting water and oil droplets spread out on the core slice, indicating that the core slice does not possess any hydrophobic or oleophobic properties. Figures 4-5 As can be seen, the core sample surface treated with the dual-hydrophobic interface modifier exhibits both hydrophobic and oleophobic characteristics. Formation water advanced at a rate of 109.1° and retreated at 121.5° on the core surface; simulated oil advanced at a rate of 62.8° and retreated at 90.3°. This indicates that the dual-hydrophobic surface formed by the dual-hydrophobic interface modifier has strong hydrophobicity while ensuring good fluid mobility within the pores, which is beneficial for opening up oil and gas channels and improving oil recovery. Water flows well in the pores and is easily flushed back; while oil droplets easily adhere to the pore walls, which also means that during waterflooding, the water flow is more likely to push away or peel off the adhered oil film.

[0037] Experimental Example 2: Core Displacement Experiment Seven dense rock cores (L≈5cm, D≈2.5cm) were selected for the experiment. The core parameters are shown in Table 1 below.

[0038] Table 1 Core parameters and physical properties

[0039] 2.1 Water Drive Experiment The equipment and instruments used include: the dual oil displacement agent described in Experiment Example 1, formation water, and core sands 50-1, 50-2, and 50-3; one core displacement device; two heating jackets; one high-pressure horizontal flow pump; one high-temperature and high-pressure reactor; one high-purity carbon dioxide cylinder; and several glass containers.

[0040] The experimental conditions were: water drive start-up pressure of 6.4 MPa, experimental temperature of 60℃, and injection rate of 0.02 mL / min (equivalent to 0.29 m / d).

[0041] When the water cut reached 99.0%, a total of 0.16 mL of crude oil was extracted from Sand 50-1, with a water drive recovery rate of 20.7%.

[0042] After injecting 0.4 PV and 0.8 PV of dual-repellent oil-dissipating agent into two core samples, sand 50-2 and sand 50-3, respectively, and allowing them to sit for 1 hour, subsequent waterflooding was carried out. The subsequent waterflooding injection pressures decreased to 5.1 MPa and 4.2 MPa, respectively, lower than the initial waterflooding pressure of 10.2 MPa. The injection pressure reductions were 21.8% and 34.3%, respectively. The experimental results are as follows: Figures 6-7 As shown in Table 2.

[0043] Table 2 Displacement Results

[0044] As shown in Table 2, the dual-hydrophobic interface modifier can significantly reduce pressure, increase injection volume, and improve oil recovery. The injected PV is positively correlated with the effect and negatively correlated with economic efficiency: the waterflooding injection pressure gradient is 191.6 MPa / m, with an oil recovery of approximately 20.7%; after injecting 0.4 PV of the dual-hydrophobic oil displacement agent, the injection pressure gradient decreases to 102.2 MPa / m, and the oil recovery increases to 32.8%; further injection of 0.8 PV of the dual-hydrophobic oil displacement agent reduces the injection pressure gradient to 86.9 MPa / m, and the recovery rate reaches 36.3%. The 0.8 PV group, due to its larger injection volume, has a higher effect, but the reagent cost doubles; the 0.4 PV group, with half the dosage, although showing a 3.5% lower recovery rate, achieves a better balance between effect and economic efficiency.

[0045] 2.2 Air-driven experiment The equipment and instruments used include: the dual oil displacement agent described in Experiment Example 1, formation water, and core sands 50-4, 50-5, 50-6, and 50-7; one core displacement device; one heating jacket; one high-pressure horizontal flow pump; a high-temperature and high-pressure reactor (including a temperature control system); a high-purity carbon dioxide cylinder; a rotary vane vacuum pump; and several glass containers.

[0046] The experimental procedure was as follows: After saturating the core with oil, the natural core was fixed in a core holder, and a heating jacket was added to maintain a high-temperature environment inside the core. A backpressure valve, gas metering, and liquid collection device were connected to the end, and a pressure sensor was connected to the gas injection end. Carbon dioxide was compressed to a supercritical state using an intermediate container, while a heating jacket was used to keep it warm and prevent liquefaction. Supercritical carbon dioxide was then used for gas-driven propulsion. The results are as follows: Figures 8-11 As shown in Table 3.

[0047] Table 3 Results of Air Drive

[0048] From Table 3 and Figure 8 It can be seen that after CO2 flooding, the gas drive recovery rate of the 0.2PV CO2-dual dewatering oil agent system (0.2PV CO2-modifier flooding) injected into the core (K=0.075mD) was 15.73%, and the final recovery rate of the 0.2PV CO2-dual dewatering oil agent system was 26.01%, which is 10.01% higher than that of CO2 gas drive.

[0049] From Table 3 and Figure 9 It can be seen that after CO2 flooding, the gas drive recovery rate of the 0.4PV CO2-dual dewatering oil agent system (0.4PV CO2-modifier flooding) injected into the core (K=0.092mD) was 15.84%, and the final recovery rate of the 0.4PV CO2-dual dewatering oil agent system was 28.19%, which is 12.35% higher than that of CO2 gas drive.

[0050] From Table 3 and Figure 10 It can be seen that after CO2 flooding, the gas drive recovery rate of the 0.6PV CO2-dual desiccant system (0.6PV CO2-modifier flooding) injected into the core (K=0.057mD) was 14.96%, and the final recovery rate of the 0.6PV CO2-dual desiccant system was 31.44%, which is 16.48% higher than that of CO2 gas drive.

[0051] From Table 3 and Figure 11 It can be seen that after CO2 flooding, the gas flooding recovery rate of the 0.8PV CO2-dual desiccant system (0.8PV CO2-modifier flooding) injected into the core (K=0.021mD) was 14.65%, and the final recovery rate of the 0.8PV CO2-dual desiccant was 33.20%, which is 18.53% higher than that of CO2 gas flooding.

[0052] The CO2-dual slug-repellent system significantly improves CO2 flooding performance, with its core effects being substantial pressure reduction and sustained enhanced oil recovery. After injection, while significantly reducing displacement pressure by approximately 65%, it dramatically increases oil recovery from about 16% in CO2 flooding to over 34%, an increase of more than 18 percentage points. The effect is clearly positively correlated with the injection volume; an injection volume of 1.0 PV yields the optimal pressure reduction and oil recovery enhancement. From 0.4 PV to 1.0 PV, the increase in oil recovery tends to level off, with the optimal slug injection volume between 0.4 and 0.8 PV achieving the best balance between technical effectiveness and economic benefits. The effect of the dual slug-repellent system does not further enhance subsequent secondary CO2 flooding.

[0053] Experiment Example 3: Oil Washing Efficiency Experiment A small amount of scrap material was extracted from the core, crushed, sieved (20 mesh), washed, and dried. This material was then thoroughly mixed with crude oil and aged at 60℃ for 24 hours. 50g of oil sand (total oil content approximately 6.8mL) was placed in two clean, dry percolation bottles. The dual oil-dissipating agent described in Experiment 1 and formation water were added to each bottle, respectively. The bottles were sealed, and the initial readings were recorded. They were then placed in a 60℃ oven to simulate the formation environment. The results are as follows: Figure 12 As shown.

[0054] from Figure 12 As can be seen, after 290 hours, the oil yield from both the dual-hydrophobic interface modifier and the formation water reached saturation, and the oil washing rate showed a trend of being fast at first and then slowing down. Specifically, the total volume of oil washed out was approximately 3.55 mL, with a cumulative oil washing efficiency of approximately 52.2%; while the oil yield from the formation water was approximately 0.8 mL, with an oil washing efficiency of 11.7%. The dual-hydrophobic interface modifier prepared in this invention has a very significant oil washing effect.

[0055] The present invention has been described according to the above embodiments. It should be understood that the above embodiments do not limit the present invention in any way. All technical solutions obtained by equivalent substitution or equivalent transformation fall within the scope of the present invention.

Claims

1. A bihydrophobic interface modifier, characterized in that, The molecular formula of the dual-hydrophobic interface modifier is C 13 H 22 F7NO4Si has the structure shown in Formula I: 。 2. The method for preparing the bihydrophobic interface modifier according to claim 1, characterized in that, Includes the following steps: (1) Under an inert atmosphere, perfluorobutyric acid was dissolved in a solvent, thionyl chloride was added to carry out an acyl chloride reaction, and the intermediate product was obtained after removing the solvent. (2) Dissolve the intermediate product and the acid-binding agent in a solvent, and then add (3-aminopropyl)triethoxysilane to carry out a substitution reaction to obtain the product.

3. The method for preparing the bihydrophobic interface modifier as described in claim 2, characterized in that, In step (1), the solvent is dichloromethane; the molar ratio of perfluorobutyric acid and thionyl chloride is 1:(1~1.4).

4. The method for preparing the bihydrophobic interface modifier as described in claim 2 or 3, characterized in that, The acyl chloride reaction includes the following steps: first reacting under ice bath conditions for 20-30 minutes, then heating to 45-55℃ and reacting for 3-4 hours.

5. The method for preparing the bihydrophobic interface modifier as described in claim 2, characterized in that, In step (2), the solvent is tetrahydrofuran; the acid-binding agent is triethylamine; and the molar ratio of the intermediate product, the acid-binding agent, and (3-aminopropyl)triethoxysilane is 1:(1.2~1.4):(1.1~1.3).

6. The method for preparing the bihydrophobic interface modifier as described in claim 2 or 5, characterized in that, The substitution reaction is carried out at a temperature of 45-55°C for 8-10 hours.

7. The application of the dual-hydrophobic interface modifier according to claim 1 in the preparation of dual-hydrophobic oil displacement agents.

8. A dual oil-repellent agent, characterized in that, It includes the bihydrophobic interface modifier, anionic surfactant, and organic solvent as described in claim 1.

9. The application of the dual-hydrophobic interface modifier according to claim 1 in crude oil recovery.

10. The application of the dual-hydrophobic interface modifier as described in claim 1 in drag reduction of oil and gas gathering and transportation pipelines in oil fields.

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